A mixed fabric is understood as a fabric which partially contains synthetic fibers and partially natural fibers, that is to say in particular, for example 65% of polyester and 35% of cotton. Customarily, overalls, jackets, shirts and similarly shaped articles are manufactured from such mixed fabrics. As a rule, these are work clothes, for example those of technician staff, for example draftsmen workshop garments and also those of physicians and soldiers. Not infrequently, these shaped articles are washed and treated in large laundries, where it is very difficult to inexpensively smooth and dry these shaped articles after washing, so that their proper appearance is restored. After the washing process, mixed fabrics of this type show an extensive formation of creases. These creases and folds must then be removed again from the shaped articles at a later stage. The formation of creases is caused, on the one hand, by the temperature which occur during washing and, on the other hand, by the spinning or pressing steps which take place after the actual washing process in order to remove the water at least partially from the shaped articles.
In order to counter this formation of creases during the washing process, special washing programs which comprise precise instructions regarding the temperatures, water levels in washing drums, cooling periods of the laundry and the like, which are to be maintained, have been developed for mixed fabrics of this type. The salient point of these prescribed washing processes is to avoid rapid changes in temperature. Moreover, the washing machines are loaded only partially so that the capacity of a washing drum is utilized only partially, in order to reduce the extent of the creasing of the shaped articles.
Two different procedures, which, however, both require the observance of special washing instructions are known for the after-treatment of such shaped articles of mixed fabric. These procedures concern smoothing and drying after the washing process. On the one hand, the shaped articles of mixed fabric are, after washing, only slightly spun and are hung up in the moist state. They are then passed through a drying chamber and are dried by a gentle air stream. Any creases present in the shaped articles cannot be removed in this way. The result of this smoothing and drying method depends on the precise observation of the washing instructions and hence on the extent to which the laundry is free from creases at the end of the washing process.
On the other hand, it is also known, while observing a special washing process, to hang up the shaped articles in the wet state and to pass them through a chamber in which steam is gently blown against them. The natural fibers (cotton and the like) thus swell to a greater or lesser extent. Due to the mere weight of the articles, they are stretched downwards, corresponding to gravity, and thus become somewhat smoother. The synthetic fibers are hardly influenced by this process. Subsequently, the shaped articles are dried with warm air. Such equipment does not operate satisfactorily since it involves a compromise between the supplies of moisture and heat. If excessively hot steam is added, the shaped articles dry out too quickly and the swelling of the fibers is inadequate. This method only serves to fix the creases, and smoothing of the shaped articles does not occur. If, however, excessively moist steam is added, there is insufficient heat for bringing the natural and synthetic fibers into a formable state, from which a smoothing process could develop. Even in this noted procedure, the shaped articles are largely creased at the end of the treatment step so that they have an unsatisfactory appearance.
The disadvantages of the known procedures are that the washing programs must be observed precisely. Mechanical dewatering of the shaped articles after the washing program represents an interference in most cases and is therefore not possible. The washing machines can be loaded only to an extent of about 50%. A high heat and power consumption, coupled with long washing times, results. A further disadvantage is that the result of the treatment is strongly dependent on the nature, manufacture and make-up of the shaped articles. Nevertheless, satisfactory results are obtained only under very restricted conditions.
It is the object of the invention to demonstrate a process and equipment, by means of which it is possible successfully to smooth, and to dry, washed shaped articles of mixed fabric, and to do this independently of the preceding washing process and the properties of the shaped article.